Sure! Here are the underlined words or phrases that need correcting in each sentence:

1. **Sentence 1:** "taking" should be **"to take."** (I never forget to take...)
2. **Sentence 2:** "concentrate" should be **"concentrating."** (prevented me from concentrating...)
3. **Sentence 3:** "about" should be **"on."** (congratulated the team on winning...)
4. **Sentence 4:** "to lock" is correct, but "before" should not be in this context. It should be **"before I went to bed."** (I remember to lock the door...)

Let me know if you need further assistance!